2011 Toyota Sienna

Comments

I don't consider 50% as being very low, which is the MAXIMUM amount routed during hard acceleration. It even partially locks, ~30%, the center "diff'l" while turning. Accelerate while turning tightly and that amount might actually grow to 50%.

I suppose that's true if driving hard on dry....although Toyota's documentation seems to be a bit vague whether it's actually 45% or 50%. Not that it really matters as hard acceleration/cornering isn't high on the old family hauler must-have list. My point was more directed at slippery conditions which is where we are interested in the awd....you won't be hammering the go-pedal so there will be lower amounts of power transfer until slippage. Unless you just get your jollys from hot-lapping a monster-van with mediocre handling at best.

Yes the frictional losses and weight require more oomph from somewhere and in this case it gets it from lower gear ratio. So even if you could turn off 90% of the frictional losses it's still far less efficient. Negative in my book regardless.

When it's all said and done the cons far outweighed the pros. Mediocre system, substantial economical/efficiency losses, run-flat nonsense....pass.

If I unintentionally implied that the 50/50 only applied under hard acceleration, my apologies. It is my understanding that any level of low speed acceleration, certainly so from a full stop, will result in approximately a 50/50 torque distribution.

Since actual road conditions cannot be determined in advance the system is designed to always assume the worse.

Stupid, yes, but when you start out with a base FWD the choices become somewhat limited.

I bought a new 2011 limited sienna last night and it rained all night and this afternoon openned the trunk and the floor of the trunk is soaked (like you described). I am pretty dissapointed. This van was just delivered to the dealer 2 days ago. I thought problems would be resolved since they have been producing them for over a year now. What dealer did you take it to? I am wondering if I can have this Toyota service department contact your service department. Who did you talk to, if you don't mind me asking? Thanks!

Actually if you look at Toyota's information on this system (Venza, Matrix, Sienna, RAV4) it applies various levels of amperage to the clutch pack during "acceleration, tight cornering, or when one or more wheels is spinning. If the ECU sends low amperage to the solenoid, a lesser amount of pressure is applied to the disc pack resulting in a smaller amount of torque directed to the rear wheels. Higher amperage sent to the solenoid produces a larger actuating force on the main clutch disks...... The amount of torque to the rear wheels is infinitely variable through the application of current as directed by the 4WD ECU up to a maximum of 45% rear and 55% front torque distribution".

I had read the 50% figure somewhere online as well but according the the docs I have here it says 45%. So it shouldn't be pulling much power at normal acceleration.

Okay, consider the design problem the engineering team faces in designing a F/awd system, "this" system.

Bottom line, like an actual FWD, once a wheel slips, FWD always a front wheel, for F/awd most likely a front wheel initially, ALL is lost.

The F/awd system must now INSTANTLY switch into "RECOVERY" mode. With any level of front wheelspin/slip, even the slightest level, the threat of loss of directional control is just to great to ignore.

So the F/awd system's next action will mean nil, TC (VDIM) is now the BOSS.

So, the engineering decision is, MUST be, at the instant the vehicle begins initially moving from a full stop, use the MAXIMUM front to rear coupling coefficient (45%, I'm okay with that). Now, as the vehicle picks up speed the coupling level can, by design, decline precipitously.

MUST decline precipitously, actually. Rising speed always means sufficient roadbed traction for the level of acceleration present. Forward momentum also becomes an important part of the traction equation.

NOT reducing the coupling level cognizant with rising roadspeed would result in premature failure of driveline components due to driveline windup and/or tire scrubbing.

So, absent your "scan-guages" ability to plot a real-time curve of roadspeed vs current flow, dutycycle, you will not be able to "see" how the F/awd system is working.

Getting close to purchasing a new Sienna SE. Hesitant to "pull the trigger" based on some comments that the build quality is not up to Toyota standards. My 97 T-100 and 05 Prius have been excellent long term vehicles - no rattles, no mechanical issues, etc. I have a quote for under invoice ($500) - thoughts on pulling the trigger? Thanks, Andy

You are correct that most lower anchors only are approved up to 45 lbs, but I'm really talking here about the tether anchors. (I should have been more clear in my original comment). I have 4 kids in convertible seats, all of which use tether anchors to improve installation and reduce head excursion, even when the seat is using seat belt path. Gee, which kid in the back row do I sacrifice since Toyota decided to eliminate one of the tether anchors back there? Sorry. I will keep my 05 awhile longer and see if they add the anchors back or I will get another brand minivan to replace this one.

This is another case of the driver's functional designs in comparison to the 2004 Sienna. Can someone at Toyota explain why they took out all the front console functionality and replaced it with four cup holders for the driver and front passenger? If I include the door bottle storage, the front seat section has places for 2 bottles and 4 cups? As stated in a previous post, this must have been designed by a man who was brain dead when it came to practical/DRIVER FRIENDLY design.

Quite happy with the front console, particularly the piece that slides back to the 2nd row. Pretty much required given that the 2nd row chairs don't have any cupholders on them.....!! I like the flat surface of the console for phones, etc and the storage down on the floor is nice as well. Wife's purse no longer slides around.

Reading the forums on the new Odyssey & Sienna tells me not to buy any one of these BUT a 2008 to 2010 used edition. Reminds me of the 1977 Chrysler Aspens, etc where a great engine was made worst by changing the wrist-pin design in the motor (I did not buy one).

I guess it depends on your priorities. We had an '05 Odyssey and IMHO the new one is far better. Uglier...but styling is far from the top when I shop vans/SUVs. I never warmed up to the previous Gen Siennas...the new one is a bit more engaging to both drive and look at. Some nice extras like the dual sunroofs, smartkey, folding mirrors. The deal killer for us was the color combos on the Odyssey...wife hates gray interiors and refused another one. If the Black Ody came with Tan interior...that's what we would be driving. I would take either new model over the previous gen.

I have a 2011 Toyota Sienna XLE and have been experiencing the same issue. Did you have to go to arbitration with Toyota or did the dealership take care of swapping the vehicle? Did you have to go through a lemon law litigation? Any information you can provide would be helpful. Car is going back for the fourth time. Water is accumulating while my car is sitting in the driveway. Had Zero issues with my 2001 Sienna.

A reporter is interested in talking with parents who own a 2011 or 2012 Kia Optima, Kia Sorento, Hyundai Elantra, Ford Focus, Honda Fit, Honda Odyssey, Mazda 5, Subaru Outback, Dodge Durango, or Toyota Sienna. If you are interested in commenting on your experience, please reply to pr@edmunds.com no later than Friday, November 30, 2011 and include your city and state of residence, the model year of your vehicle and the age of your child/ren.

Am very disappointed in 2011 sienna 2-star rating for frontal crash, passenger. Assuming 2012 won't be any different but see NHTSA will test 2012. Am surprised there aren't more people complaining about this. Bought ours based on IIHS ratings, then NHTSA came out with theirs and not good! Am looking into real-world crash results and maybe larger SUV would be better.

First off, safecar.gov shows the '11 Sienna as 3-stars on the frontal crash so i'm not sure where you got the 2.

Regardless you have to take all of these ratings with a grain of salt. All of the '11+ tests are at a higher rating scale so they can't be compared to prior tests. There's a lot of vehicles not even tested with the new standards at this time.

Bigger does not equal better in a single-vehicle crash. If anything the heavier a vehicle the harder the deceleration. So if you can pick your crash...go for a small/light vehicle for a single vehicle crash and a big heavy one for multi-vehicle. The "mini" vans are far from light vehicles...in fact there's not many SUV's that are bigger. Sienna is the same size or bigger than most of the SUV's out there with the exception of the Suburban/Expedition XL.

I don't worry too much about the ratings...the real world facts are all minivans are very safe. I persoanlly like the IIHS anyway because they seem to show and give more details

Yes, the frontal crash overall rating is a 3 star; I was referring to the front passenger rating which is a 2 star (driver is a five star, which is great and what it should be). However, with some older children now sitting up front in this van, I'm really not liking the 2-star front passenger rating in case of a crash. So I've been debating trading Sienna for Odyssey (had one before Sienna, my Ody went over 140k with no tranny problems, but am reluctant to get back to that, even though Odyssey has 5-star crash-test ratings where Sienna does not)... or going with something like Volvo XC90 or a larger SUV (Tahoe) but hate the gas guzzle. I still think a Tahoe would "win" in a crash with my Sienna or an Ody. That's the dilemma. Do wish they'd test the 2012 Sienna, if it scores 5 stars, I could just trade for that. Just not sure why Sienna 2011 did so poorly -- 2-star rating for a front passenger is just NOT acceptable. Especially when Odyssey and a few other vehicles (Volvo XC60) get 5 stars in that same seat.

I also will go back and look at IIHS tests for 2011 Sienna, as you mention there is more detail, but NHTSA test result is simply abysmal in my opinion and just not acceptable for a "family" vehicle. That front passenger should get no less than a 5-star, just as the 2011 Odyssey has tested in the newer more stringent NHTSA tests.

I looked again and there's actually a lot more detail on the NHTSA site. You can drill down to the 80+ page test report with pics. It looks like the threshold levels on the dummy are all very low, although the passenger is higher than the drive. Compartment looks quite good and dummy appears to hit the right spots. I still can't see an individual star rating between driver and passenger, nor can I find what the star ratings actually mean. I know in the past a 2-star meant you were getting hurt, but it doesn't look like that's even close to the case now. One thing that really seems weird to me is that when they test these, the passenger seat is basically jammed against the dash. I don't know why anyone would ride like. If you look at the pictures it seems like they have the passenger seat as far forward as it will go, including the seat-back.

The only thing a Tahoe has on the Odyssey/Sienna is a little higher ride and a few hundred pounds. The size is almost identical but the space is a HUGE difference. We had a Tahoe before and the minivan is a huge upgrade in terms of space behind the front seats.

We also had an '05 Odyssey and were quite happy with it. The new Ody is rated very highly but it just wasn't a major concern for me. I feel they're all very safe and none have any specific test failures. It appears even a two-star is quite safe based on the new ratings. Obviously everyone has different priorities when buying so that's your call. I personally can't imagine trading because of what appears to be a relatively minor difference between best and worst. It's kind of like reliability ratings...vehicles have gotten so reliable that the difference between best and worst is hardly worth mentioning.